You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
tls-compatibility
About this tag
The tls-compatibility tag covers discussions about TLS version interoperability, particularly the challenges introduced by TLS 1.3. A recurring theme is the breakage of mutual TLS (mTLS) workflows in IIS Express on Windows 11, where the kernel-level TLS handling in http.sys and Schannel prevents reliable client certificate requests after the initial handshake. Microsoft engineers have acknowledged this as a structural limitation with no near-term fix for the lightweight developer server. The tag also includes workarounds and outlooks for developers and administrators managing TLS configurations on Windows systems.
Windows developers and administrators who depend on client-certificate (mTLS) workflows will need to keep using workarounds: a structural limitation introduced by TLS 1.3 and the way Windows handles TLS in kernel (http.sys / Schannel) means IIS Express on Windows 11 cannot reliably request a...